On their first visit to the new stadium, having come out on the right side of play-off finals in 1992 and 2000, Darren Ferguson’s League One men ensured they made it three wins out of three at the home of English football.

Loanee Josh McQuoid’s first goal for the club, following an absolute howler from keeper Tommy Lee, put Posh in dreamland in only the sixth minute. Shaun Brisley’s thunderous header towards the end of the period – after Chesterfield had dominated and spurned two great opportunities - sent his club’s fans into a state of delirium.

That following of almost 20,000 weren’t allowed to enjoy the second half quite as comfortably though after Eoin Doyle finished off powerhouse midfielder Sam Morsy’s fine work. And that state of worry only grew when the same player was kicked off the ball by the petulant Joe Newell to leave his team up against it.

But in the end it didn’t matter as Mark Little’s fantastic run from right back was ended by the third Spireites’ player to try and stop him, Liam Cooper, to give record signing Britt Assombalonga the chance to wrap things up.

He duly obliged to register his 28th goal of the campaign and send Posh fans home celebrating their first senior trophy and enjoying one of the greatest days in the outfit’s 80-year history.

Higher-level Posh went into the Football League’s showcase cup game as slight favourites – but on the back of a miserable run of form which has seen them lose five of their last seven.

So Chesterfield had high hopes of completing their second Wembley success in three seasons. Especially as they are also targeting promotion to the same level as their Cambridgeshire-based opponents.

It was no surprise then that the Spireites started confidently by zipping the ball around the hallowed turf. They were unlucky not to be awarded an early penalty when Doyle appeared to beat Brisley to the ball on the edge of the box and was upended. Andy D’Urso waved played on and was clearly unsure if a foul was committed but the replays suggested one thing was certain, and that was that United’s number four didn’t get any contact on the ball at all.

Right-sided player Danny Swanson was impressive in the opening stages for United and his burst across the pitch created a chance for Newell. The energetic midfielder’s effort was deflected over excellently by Ian Evatt.

But Peterborough didn’t have to wait long for their next chance as from Grant McCann’s resulting corner, Brisley was left in acres of space. Lee made a complete hash of the defender’s header and McQuoid took advantage by poking home the rebound to hand his men a dream start.

Ace marksman Britt Assombalonga had been kept fairly quiet by Chesterfield’s backline until the 15th minute when he was played in delightfully by Swanson’s clever round-the-corner flick. The powerful frontman went down under pressure from keeper Lee but was on his way to ground long before there was a hint of contact and the opening came to nothing.

Despite being rocked by going a goal behind, the League Two promotion-chasers reacted positively, got on top and enjoyed a sustained spell of pressure.

Nathaniel Knight-Percival blocked a goal-bound Sam Bird header and Brisley denied Doyle as the side in blue, against United in their changed white strip, poured forward. A Doyle cross evaded everyone before wing-wizard Gary Roberts embarrassed himself by trying to con the referee with a blatant dive, much to the anger of Brisley.

Posh, operating with a midfield diamond, couldn’t get to grips with the slick and stylish Derbyshire outfit. And Paul Cook’s charges should have at least pulled a goal back, or probably been level, when they were presented with two golden opportunities as the opening 45 wore on.

First, Tendayi Darikwa jinked his way to the byline and laid it on a plate for Morsey. Somehow, inexplicably, he skewed horribly wide from eight yards. Then, Evatt was found at the back post by Roberts’ free-kick but – despite being unmarked – could only head straight at Bobby Olejnik.

Chesterfield were quickly made to pay for their wastefulness as Peterborough scored against the run of play to double their advantage. Swanson’s cross was met excellently by Brisley, who nearly headed through Michael Bostwick to meet the ball, and it was two.

Despite being second best for much of the half, the London Road club went into the break with a more-than-handy two-goal advantage.

It would have been three had Assombalonga not fluffed his lines when found by McQuoid inside a couple of minutes of the restart. With his goal-scoring record this season, having netted 27 times, you’d have fancied him to hit the back of the net.

Swanson curled one over with his left foot as Posh’s confidence grew while they attacked towards the end their fans occupied.

However, this time it was the Spireites who found the net when they weren’t on top to give themselves hope. Morsy powered forward, which drew the attentions of Bostwick, Brisley, and squeezed the ball into the path of Doyle who kept his composure to reduce the arrears.

At the other end, McCann drew a decent stop from Lee who must have wished he had shown such safe hands in the opening few minutes.

Newell’s moment of madness on the touchline left Ferguson’s heroes to battle on with 10 men for about 25 minutes.

Yet it didn’t matter as Little’s marauding run was ended in the area in the final quarter of the tie by Cooper and Posh’s number nine coolly slotted his spot-kick home to restore their two-goal advantage.

It was one they never looked like relinquishing with Swanson – who should have squared to Assombalonga rather than shooting – wasting their best chance to rub more salt in their opponents’ wounds.

Olejnik was only called into action once in injury time to deny Mason Bennett and Morsy what would have been nothing but consolations.

There was still time for substitute Lloyd Isgrove to streak through and nearly round off his impressive cameo but Lee used his legs to good affect.